Vented studyoke on slip-between-center driveshaft

Abstract

A vented slip joint assembly includes a first shaft with a first end having an externally splined portion. A second internally splined shaft is drivably connected at a first end to the first shaft. A seal sealingly engages the first shaft and the first end of the second shaft. A vent is provided in the first shaft to provide fluid communication to the second end of the first shaft.

What is claimed is: 
     
       1. A vented slip joint assembly comprising: A first shaft having an outer surface and a first end with an externally splined position;   a second shaft having a first end with an internally splined portion, a cap at a second end thereof to form a first cavity inside the second shaft, the splined portion of the second shaft drivably connected to the splined portion of the first shaft;   a seal having an inner surface, the seal sealingly engaged with the first and second shafts to define a second cavity bounded by the outer surface of the first shaft, the inner surface of the seal, and the first end of the second shaft, and the seal further defining a third cavity including the first cavity of the second shaft, the inner surface of the seal, and the outer surface of the first shaft; and   a vent provided in the first shaft, the vent having a first end in fluid communication with the second cavity, the vent extending through the first shaft, and having a second end in fluid communication outside the third cavity.   
     
     
       2. A slip joint assembly according to claim 1, wherein the vent comprises: one of the internally and externally splined portions having a spline removed to accommodate fluid communication between the second cavity under the seal and the first cavity between the cap and the first end of the first shaft; and   said first shaft having an axial bore therethrough for fluid communication between the first cavity through the first shaft outside the third cavity.   
     
     
       3. A slip joint assembly according to claim 2, wherein the seal comprises a rubber boot secured to the first and second shafts to form the second cavity therebetween. 
     
     
       4. A slip joint assembly according to claim 1, wherein the vent comprises said first shaft having a bore provided therein, the bore having a first end in fluid communication with the second cavity under the seal, the bore providing fluid communication through the first shaft, and a second end for fluid communication outside the third cavity. 
     
     
       5. A slip joint assembly according to claim 4, wherein the bore further comprises an axial bore from a second end of the first shaft in fluid communication outside the third cavity and a radial bore in fluid communication between the axial bore and the second cavity under the seal. 
     
     
       6. A vented slip joint assembly comprising; a first shaft having a first end with an externally splined portion and a second end;   a hollow driveshaft having a first cavity within the drive shaft, the driveshaft drivably connected to the second end of the first shaft;   a second shaft having a internally splined portion drivably connected to the splined portion of the first shaft;   a seal sealingly engaged with the first and second shafts to define a second cavity bounded by the seal and the first and second shafts; and   a vent provided in the first shaft, the vent having a first end in fluid communication with the second cavity, the vent extending through the first shaft and having a second end in fluid communication with the first cavity of the driveshaft.   
     
     
       7. A slip joint assembly according to claim 6, wherein the vent comprises: a third cavity defined by the internally splined portion of the second shaft and the first shaft;   one of the internally and externally splined portions having a spline removed to accommodate fluid communication between the second cavity and the third cavity; and   said first shaft having an axial bore therethrough with a first end in fluid communication with the third cavity, the bore extending through the first shaft and having a second end in fluid communication with the first cavity.   
     
     
       8. A slip joint assembly according to claim 6, wherein the vent comprises said first shaft having a bore provided therein, the bore communicating at a first end with the second cavity under the seal, the bore extending through the first shaft, and the bore having a second end in fluid communication with the first cavity. 
     
     
       9. A slip joint assembly according to claim 8, wherein the bore comprises an axial bore from a second end of the first shaft, the axial bore having a first end in fluid communication with the first cavity and a second end in fluid communication with a radial bore provided in the first shaft, the radial bore having a first end in fluid communication with the axial bore and a second end in fluid communication with the second cavity under the seal. 
     
     
       10. A slip joint assembly according to claim 6, wherein the seal comprises a rubber boot secured to the first and second shafts to define the second cavity therebetween. 
     
     
       11. A method of venting a slip joint assembly comprising; providing a first shaft having a first end with an externally splined portion;   providing a second shaft having a closed first end with an internally splined portion defining a first cavity therein, the second shaft drivably connected to the first end of the first shaft;   providing a seal to sealingly engage the first and second shafts to create a second cavity therebetween defined by the seal and the first and second shafts; and   providing a vent in the first shaft having a first end in fluid communication with the second cavity and a second end in fluid communication outside the first and second cavities.   
     
     
       12. A method according to claim 11, wherein the vent is provided by removing a spline from one of the shafts to provide fluid communication between the first and second cavities and providing an axial bore through the first shaft to provide fluid communication outside the first and second cavities. 
     
     
       13. A method according to claim 11, wherein the vent is provided by: providing an axial bore in the first shaft at a second end opposite the first end, the axial bore having a first end in fluid communication outside the first cavity; and   providing a radial bore in the first shaft, the radial bore having a first end in fluid communication with the second cavity and a second end in fluid communication with the axial bore.